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Monday, November 14, 2011

Making Hot Processed Soap

I have been making soap for several years now but
I had never made hot processed soap before this last weekend.

If you are not a soap maker you may not realize that there are two ways to make
soap. One is called cold processed and the other hot processed. Here is the
difference:

Cold Processed (CP): This method involves combining your
liquid/lye mixture with your oils and stirring until the mixture thickens (also
known as “trace”) . Then pouring the mixture into molds. In a day or two you
unmold, cut the bars and let the soap lay out on a flat surface to cure anywhere
from 3 to 6 weeks depending on the recipe. This ensures the soap is free from
all traces of lye.

Hot Processed (HP): You follow the same procedures as CP but
instead of pouring into your mold you keep cooking the soap. The soap is heated
and cooked all the way through to the end (meaning there is no traces of lye
left in the soap). After you remove it from the mold you can cut the bars and
pretty much use them right away.

I have always used the cold processed method for many reasons (the soap is
smoother in texture, looks nicer, essential oils are easier to add, etc..). But
every now and again I like to have a little fun time with my soap making. So
over the weekend I made a batch of HP soap in my crockpot. It was pretty simple
to make (this is coming from an experienced soap maker!), and it was fun.

If you are not familiar with making soap you will want to make sure you are
prepared with information and the proper equipment before you start. I don’t go
into a lot of that in this blog post mostly because I already have a few web
pages on making soap (
http://www.thefamilyhomestead.com/homesteadcrafts.htm#Lets%20Make%20Soap
) and an entire ebook on how to make soap, step by step filled with pictures and
information (
http://crystalscountrystore.com/handmadesoapebook.htm ) … so this
little tutorial is showing just the basics of what I did. Please be
knowledgeable on proper soap making procedures and cautions concerning the use
of lye.

First of all I gathered together all my ingredients. In the picture below you
can see my oils all measured out by weight (3 types of oils), the little dark
colored bottle is my scent oil (I had a 1 oz sample bottle of Lemon Sugar
fragrance oil and it was perfect for this batch) and on the right my water and
lye…

Here is my mold… I used a small cardboard box (this recipe needs a mold that
will hold 48 oz) lined with plastic..

I started by setting my crockpot on high and adding the coconut oil (any hard
oils are added first to melt). While that was melting I mixed up my water and
lye. When the lye and water were mixed and the coconut oil was melted I turned the
crockpot to low and then added the olive oil and the castor oil to the crockpot…

Now it was time to add the lye/water mix.. unlike CP soap, the temperature of
the oils and lye don’t matter when making HP soap. When you add the lye/water
mix you should be stirring constantly, I found this a little hard to do and take
the pic! :) ..

As soon as it was stirred in I switched to my stick blender and mixed it up..

Until the mixture reached “trace”… this is where the soap is looking like thick
pudding/gravy...
(it is can be hard to get a good pic of trace..).. Then put the lid on the
crockpot and wait..

Now this is the point it would be put into molds if I was making CP soap.. but
instead I continued to cook the soap and watched as it went through the various
stages of its chemical reaction called, saponification.. this is the process of
oils, water&lye becoming soap…

After about 15 to 20 minutes my mixture was looking like mashed potatoes..

After another 20 or so minutes my soap looked a bit like applesauce in texture..

And another 20 min later I had a waxy Vaseline look. I touched a bit of the soap
and rubbed it on my fingers and it felt like soap, then I did the zap test.. put
a little on my tongue. If there had been any lye still left in the soap I would
have felt a little zap.. but I did not, so I knew I had reached my goal.

Then I added my scent oil ..

Now I was ready to spoon it into my mold. I had to spoon the soap into the mold and
then every so often tap the mold on the counter to make sure I got any air
bubbles out. The soap at this point is very thick to work with. When I got it
all in the mold I used a piece of plastic wrap to help smooth the surface..

24 hours later I took it out of the mold..

24 hours after that I cut it into bars. I ended up with about 9 (5.25 oz)bars…

My soap is still a bit soft so I plan to let it sit and harden up before I use
it. I suspect the reason it is still on the soft side is because the soap is
made mostly from olive oil (olive oil takes longer to harden up than other
oils). I am excited to try it out when it is done. Olive oil soaps are extremely
mild and gentle on your skin.

This is really neat! We grew up making our own soap, my mom's hobby and income. People would always talk about it as "standing over the kettle and boiling the soap..." -My mom made cold pressed. Now I "see" minus the crockpot, what the old timers were meaning, I had thought it had to do with wood ashes they got their lye from! We will have to give it a try. Thanks for the tutorial!

Question for ya! I made CP soap once! It hardened and everything and I figured out the process, but the bars are so slimy when wet. I am hesitant to give anyway because the bars are so slimy after you use them. Do you have an experience with this? I think I used coconut oil and olive oil. Are homemade soap bars of pretty much the same texture as store bought or is the slimy-ness the norm?

The HP soap sounds pretty much easy. Especially if I can use my regular crockpot and not have to get a separate one.

Thanks for this post! I've been crocheting dish cloths and a bar of homemade soap would make a great gift to go along with the dishcloth.

Carol.. if there is still lye left, you just cook it for a little longer.

Gina, it sounds like it is a recipe issue. Not all recipes are the same.. but recipes high in olive oil can tend to be this way. Olive oil soap is the best for the skin so I guess there is a give and take in the situation.

Anon.. You can add color when you had the fragrance oil (I like the natural look so I never color my soaps and forgot to mention that this could be added :).. the recipe can be doubled (and a bigger crockpot used).. BUT.. make sure you run the oil amounts through a lye calculator to verify the lye amounts.. they don't always necessarily double in a recipe..

I'm not sure exactly why it would be crumbly... my first question would be.. are you sure your weight measurements were accurate? Also I've read over stirring could cause problems as well. Another issue could possibly be that when you put the soap in the mold, you did not pack it down firm enough..